The outcome was almost certain death (chance of eliminating or negotiating with the hijackers and safely landing the plane were slim to say the least). The circumstances of the terrorists' plans were understood by the passengers, they could only intervene and diminish the impact of the terrorists' plans.
The passengers who intervened are called heroes and it is noted that they gave their lives. If an altercation inflight had caused a bomb to go off, it may never be determined exactly why the terrorists "set it off" at that place or time.
I figure a person who brings a bomb on a plane as being someone committed to using it. The only legitimate bombs I can recall either went off in flight, were detected before the flight, or were used in "negotiations" on the runway (the incident I recall ended with the plane blowing up with passengers in front of cameras). It doesn't seem likely that they will surrender their bomb if they get their way (e.g. prisoners released).
I have no problems calling these thugs terrorists (they have attacked but hidden their motives, no one has stepped forward yet to take responsibility - thus the "cowards" label still fits). I've read several press reports that called them "freedom fighters", if that means they fight freedom then I agree but they certainly aren't fighting for freedom. Isolating an oppressive regime from outside influences doesn't beget anyone freedom.
One final bit of semantics, these are being called hijackings but since the planes were being flown by the "hijackers" with no intent to land, they were either "plane-jacking" or more succinctly "joyriding". I'm not familiar with other circumstances where hijackers killed the pilots and took over flight in air.
See Mulder's post #45 where he states :"One would have to be fairly certain that the hijacker doesn't just want to land at a different locale. One could kill an entire plane-load of people if the motive is misjudged."
Sounds to me that he thinks if a brave passenger jumps on a hi-jacker, and the hi-jacker detonates a bomb, the person who jumped the hi-jacker is to blame.
My way of thinking is, if someone is holding a gun to my head (not necessarily literally), I am NOT going to think them trustworthy enough to take their word when they say "I'm not going to hurt you if you do what I tell you." That is sheep mentality, and I'm not a sheep. I will punch, kick, bite, scratch, hit, curse, spit, pour, swing, poke, prod, knee, and elbow ANY part of a person that is threatening my life. If it weren't for the sheep that initially espoused the "Just give them what they want, and they won't hurt you" idea, there would be far less criminal acts. Perpetrators would fear the consequences of their actions.